Spinnerette



J. OGDEN ETAL SPINNERETTE Filed April 29, 1959 Aug. 21, 1962 FIG.3

F'IG.4

INVENTORS JOSEPH OGDEN PERCY J. ARMENY .2. M We.

ATTO NEYS 3,949,753 Patented Aug, 21, I962 tice 3,049,753 SPINNERETTEJoseph Ggden, Maywood, and Percy J. Armeny, Roselle Park, NJ.,assignors, by mesne assignments, to Engelhard Industries, Inc, Newark,NJ., a corporation of Delaware Filed Apr. 29, 1959, Ser. No. 809,742 8Claims. (Cl. 18-8) The present invention deals with a spinnerette forthe extrusion of viscous synthetic substances of filament formingability, and is concerned in particular with a spinnerette compositionespecially suitable therefor.

This application is a continuation-in-part of application Serial No.688,228, filed October 4, 1957, and now abandoned.

Spinnerettes for the extrusion of viscous substances in the spinning ofartificial filaments, e.g. nylon, rayon, etc., usually comprise a platein the form of a disc or cup, or the like, provided with a plurality oforifices formed therethrough and through which the viscous mass isextruded to form filaments.

In the spinning of certain artificial filaments, spinnerettes composedof base metals such as nickel, nickel alloys, and stainless steels, have'been found suitable. However, such spinnerettes are not alwayssatisfactory under severe operating conditions and are in particular notespecially suitable in the spinning of artificial filaments of syntheticpolyamides and other polymerization products or fibre forming abilitywhere spinning takes place at ele- 3O vated temperatures and underotherwise exacting operating conditions resulting from the nature of theextrusion mass. Although spinnerettes of stainless steel have been foundsuitable where thick-walled spinnerettes are employed, e.g. in the nylonprocess, the spinnerettes have not been entirely free from undesirablewear and corrosion. It is a critical requirement that the walls of theorifices and especially capillary discharge orifices are smooth and thatthe discharge opening is in the form of a sharply defined edge in theplane of the spinnerette bottom. When such sharp edge becomes rounded orotherwise worn due to oxidation -or corrosion under the influence of thehigh temperatures attendant with extrusion of heated synthetic viscousmasses, the spinnerette must be discarded and scrapped because thefilaments no longer are uniformly extruded.

Furthermore, the polished surface of the orifice walls and the sharpcontour of the outlet orifice edge are subjected to the abrasive actionof certain types of treated yarns, especially those known as dull yarns,and may otherwise be deleteriously affected by the cleaning processes ateven higher temperatures, whereby the life of the spinnerette becomeslimited or otherwise abnormally decreased.

It is an object of the present invention to provide a spinnerettecharacterized by a longer life under adverse spinning conditions thanthat of spinnerettes heretofore known. It is another object of thepresent invention to provide a spinnerette which shall be suitable forthe spinning of artificial filament and the like from syntheticmaterials under substantial extrusion pressures. -It is a further objectof the present invention to provide a spinnerette which is resistant toabrasion and substantially free from corrosion, erosion and oxidation atelevated temperatures, and especially substantially free from suchcorrosion, erosion and oxidation at critical portions of the extrusionorifice. Other objects and advantages of the invention will appear fromthe description hereinafter following and the drawings forming a parthereof, in which:

FIGURE 1 illustrates a top plan view of one type of spinnerette,

FIGURE 2 is a fragmentary enlarged vertical sectional view through thespinnerette wall,

FIGURE 3 is a transvxerse vertical sectional view through an extrusionapparatus including another type of spinnerette,

FIGURE 4 is a fragmentary enlarged vertical sectional view through aspinnerette wall having a modified form of orifice formed therethrough,and

FIGURE 5 illustrates a fragmentary sectional view of anothermodification of the invention.

According to the present invention, there is provided a spinnerettecomposed of a sintered metal compact containing essentially a finelypowdered carbide of tungsten mixed with a finely powdered platinum groupmetal as a binder, said compact being in the shape of a plate or cuphaving a plurality of spinning orifices formed therethrough, whereby theparticular spinnerette composition is not only resistant to corrosionand oxidation, but preserves and maintains the sharply defined edges ofthe spinnerette orifices in the plane of the extrusion face of thespinnerette, which would otherwise flake or erode particularly as aresult of abrasion and corrosion conditions under the influence of hightemperatures and pressures to which the viscous spinning mass issubjected.

In the manufiacture of the spinnerette, finely divided tungsten carbideis mixed with one or more of the platinum group metals in finely dividedform, pressed in a suitable die, e.g. a cup-shaped die or disc, andsintered, preferably in a reducing atmosphere, until the mixture isintimately bonded by virtue of the ability of the platinum group metalsto form a strong bond with the tungsten carbide. Thereafter, the blankcompact is subjected to orifice drilling operations such as by diamondlapping drilling, ultrasonic drilling or electrical arc drilling, whichare known drilling methods.

The metal composition herein contemplated ranges from to 99% tungstencarbide and from 1% to 20% platinum group metal.

One suitable composition consists of 5% platinum, the rest tungstencarbide.

Another suitable composition consists of 15 platinum, the rest tungstencarbide.

One or more of the platinum group metals may be substituted for theplatinum.

The utilization of the composition hereinabove set forth forspinnerettes results in an extremely long spinnerette life even underthe most adverse spinning conditions since the platinum group metalbinder is resistant to corrosion and maintains its bond function under awide range of elevated temperatures and under corrosive conditions athigh temperatures, while the tungsten carbide provides for the highhardness and smoothness especially desirable for spinnerettes inaddition to its corrosionresistance.

Attempts were made to use a spinnerette made of a conventional tungstencarbide composition which normally employs cobalt as a binder, but itwas found that such conventional tungsten carbide compositiondeteriorated in use due to the corrosion of the cobalt, which renderedthe composition entirely unsatisfactory for use under spinningconditions.

Regarding the drawing, FIGURE 1 illustrates a spinnerette in the form ofan extrusion plate or disc '1, constructed in accordance with theinvention, and which is provided with extrusion orifices 2.

Other types of spinnerettes to which the invention is applicable may bein the form of cups, or cups and discs having insert members positionedtherein with the insert members each having a single orifice 2 formedtherethrough and with the inserts formed of the material of theinvention.

The number of extrusion orifices in the spinnerette ranges from to 500depending on the number of such orifices as are required. The plate,disc, cup or insert of the material through which an orifice or orifices2 are formed has a thickness of from about 0.125 inch to about 1.0-inch.

FIGURE 2 shows a particular form of orifice through the thickness of thespinnerette plate 1, which is in the form of a plate composed of thesintered tungsten carbideplatinum group metal composition 3, which isprovided with an inlet face 4 having inlet portions of the orifice 2formed therethrough, which is provided with an outlet face 5 havingoutlet portions of the orifice formed therethrough and terminating inthe plane of the outlet face.

In the particular orifice of FIGURE 2, the orifice comprises acylindrical inlet 6, a cylindrical outlet 7 of less diameter than saidcylindrical inlet and known as the spinnerette orifice capillary bore,and a tapered intermediate portion 8 connecting said inlet and outlet.

FIGURE 3 shows a cup-shaped type of spinnerette according to the presentinvention as applied to an extrusion apparatus.

The cup-shaped body 9 of the composition 3 as hereinabove described, isprovided with a plurality of extrusion orifices 10. The spinnerette maybe attached to the extrusion apparatus in well-known manner, e.g. bymeans of the flange 11 at the end of an extrusion tube or pipe 12between gaskets 13.

FIGURE 4 illustrates a modified form of spinnerette orifice formedthrough the plate 1 or cup-shaped body 9. The modified orifice is in theform of a cylindrical capillary bore 1 1 formed through the thickness ofthe spinnerette.

FIGURE 5 illustrates another modification of the invention wherein thespinnerette plate 1 is composed of stainless steel or other metal oralloy wherein the orifices 2 are replaced by comparatively largeapertures 15 formed therethrough and with inserts 16 nested in theapertures, the inserts being composed of the material of the invention.

The cylindrical outlets or capillary bores 7 and 14 have a diameter offrom about 0.003 inch to about 0.0625 inch, with the length thereofbeing from about .005 inch to about 1.0 inch depending upon the type oforifice employed, e.g. an orifice of the type according to FIGURE 2 orof the type shown by FIGURES 4 and 5.

With spinnerette orifices within the dimension ranges above set forth,certain critical conditions determine the quality of the spinneretteorifice walls and consequently the quality of the filaments extrudedthrough such orifices. These conditions require that the walls of theorifice be smooth and that critical portions of the orifice have asharply defined and absolutely uniform cross-sectional contour. Thecritical portions of the spinnerette orifice are indicated at locationsA and B in FIGURE 2 and at B in FIGURE 4.

In the case of spinnerettes composed of stainless steels, for which thespinnerette of the invention is an improvement, the critical portions Aof the orifice are apt to develop small burrs during the drillingoperation. While not every orifice will develop such burrs, it isdifficult to control the metal so that every orifice in a spinnerettehaving a plurality of orifices is free of such burrs. The greater thenumber of orifices, the greater the difficulty of providing uniformityamong the orifices. Once a burr is formed at a location A, a removalthereof provides a small chamfer which destroys the uniformity of theorifice in comparison with the other orifices. When the burr is present,there is a disturbance of flow of the extruding mass which deleteriouslyalfects the extruded filament. When the burr is removed, the chamfercreated by the removal alters the length of the capillary bore whichaffects the pressure drop of the extruding mass and provides anon-uniform filament in comparison with filaments extruded through otherorifices in the spinnerette plate. Non-uniformity of the filamentsresults in variation in denier which in turn varies the dyeing qualitiesand strength of the filaments.

Consequently, such conditions in spinnerette orifices of the dimensionranges described critically affect the extruded filaments, and it isessential that all the orifice Walls and all the sharply defined orificeoutlets in the plane of the extrusion face be dimensionally uniformthroughout the spinnerette plate.

With the material of the invention, its composition nature is such thatburrs do not occur during the orificeforming operations and all thecross-sectional portions of the orifice and the outlet edges are sharplydefined and are of uniform dimensions.

As stated above, the conditions described may not be critical withorifices having dimensions outside the scope of the ranges set forth,but such conditions are definitely critical within the orificedimensions of the invention.

It is apparent that the extrusion apparatus shown is merely illustrativeof one mode of application for the spinnerette of this invention, otherextrusion apparatus being, of course, applicable within the scope of theappended claims.

What is claimed is:

1. A spinnerette comprising a plate portion having an inlet face and anoutlet face, a plurality of extrusion orifices passing through thethickness of the plate, the material defining the orifices beingcomposed of a sintered mixture of tungsten carbide powder and from onepercent to twenty percent of a platinum group metal powder, at least aportion of the length of each orifice having cylindrical wallsterminating in the outlet face.

2. A spinnerette comprising a plate portion, a plurality of extrusionorifices passing through the thickness of the plate, the materialdefining the orifices being composed of a sintered mixture of tungstencarbide powder and from one percent to twenty percent of a platinumgroup metal powder, at least a portion of the length of each orificehaving cylindrical walls of from about 0.003 inch to about 0.0625 inchdiameter, the cylindrical walls having a length of from about 0.005 inchto about 1.0 inch.

3. A spinnerette comprising a plate portion, a plurality of extrusionorifices passing through the thickness of the plate, the materialdefining the orifices being composed of a sintered mixture of tungstencarbide powder and from one percent to twenty percent of a platinumgroup metal powder, at least a portion of the length of each orificehaving cylindrical Walls of from about 0.003 inch to about 0.0625 inchdiameter, the cylindrical walls having a length of from about 0.005 inchto about 1.0 inch, the plate having a thickness of from 0.125 inch toabout 1.0 inch.

4. A spinnerette according to claim 3, wherein the plate is a metalplate having a plurality of apertures formed therethrough, an insertmember nested in each aperture, one of said apertures formed throughsaid insert member.

5. A spinnerette comprising a plate portion, a plurality of extrusionorifices passing through the thickness of the plate, the materialdefining the orifices being composed of a sintered mixture of tungstencarbide powder and from one percent to twenty percent of a platinumgroup metal powder, at least a portion of the length of each orificehaving cylindrical walls of from about 0.003 inch to about 0.0625 inchdiameter, the cylindrical walls having a length of from about 0.005 inchto about 1.0 inch, the plate having a thickness of from 0.125 inch toabout 1.0 inch, said plate having an inlet face and an extrusion face,the cylindrical walls terminating in partly defined edges in the planeof the outlet face.

6. A spinnerette comprising a plate portion, a plurality of extrusionorifices passing through the thickness of the plate, the materialdefining the orifices being composed of a sintered mixture of tungstencarbide powder and from one percent to twenty percent of a platinumgroup metal powder, at least a portion of the length of each orificehaving cylindrical walls of from about 0.003 inch to about 0.0625 inchdiameter, the cylindrical walls having a length of from about 0.005 inchto about 1.0 inch, the plate hav- 5 ing a thickness of from 0.125 inchto about 1.0 inch, said plate having an inlet face and an extrusionface, the cylindrical walls terminating in sharply defined edges in theplane of the outlet face, the orifices each having an inlet portionpartly through the thickness of the plate and merging with saidcylindrical walls.

7. A spinnerette according to claim 5, wherein the material consists oftungsten carbide powder and fifteen percent platinum powder.

8. A spinnerette according to claim 5, wherein the material consists oftungsten carbide powder and five percent platinum powder.

References Cited in the file of this patent UNITED STATES PATENTSFeussner et a1 May 14, 1935 Estes et a1 Sept. 28, 1937 Jones Feb. 15,1944 Lucas Jan. 24, 1956 Goetzel et al July 3, 1956 DeWolf June 24, 1958FOREIGN PATENTS Great Britain Apr. 6, 1933 Great Britain Jan. 27, 1954

